1/*
2 * Copyright (c) 2008, 2009, Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met:
7 *
8 *     * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *     * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 *     * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#ifndef BMPImageDecoder_h
32#define BMPImageDecoder_h
33
34#include "BMPImageReader.h"
35#include <wtf/OwnPtr.h>
36
37namespace WebCore {
38
39    // This class decodes the BMP image format.
40    class BMPImageDecoder : public ImageDecoder {
41    public:
42        BMPImageDecoder(ImageSource::AlphaOption, ImageSource::GammaAndColorProfileOption);
43
44        // ImageDecoder
45        virtual String filenameExtension() const { return "bmp"; }
46        virtual void setData(SharedBuffer*, bool allDataReceived);
47        virtual bool isSizeAvailable();
48        virtual ImageFrame* frameBufferAtIndex(size_t index);
49        // CAUTION: setFailed() deletes |m_reader|.  Be careful to avoid
50        // accessing deleted memory, especially when calling this from inside
51        // BMPImageReader!
52        virtual bool setFailed();
53
54    private:
55        inline uint32_t readUint32(int offset) const
56        {
57            return BMPImageReader::readUint32(m_data.get(), m_decodedOffset + offset);
58        }
59
60        // Decodes the image.  If |onlySize| is true, stops decoding after
61        // calculating the image size.  If decoding fails but there is no more
62        // data coming, sets the "decode failure" flag.
63        void decode(bool onlySize);
64
65        // Decodes the image.  If |onlySize| is true, stops decoding after
66        // calculating the image size.  Returns whether decoding succeeded.
67        bool decodeHelper(bool onlySize);
68
69        // Processes the file header at the beginning of the data.  Sets
70        // |*imgDataOffset| based on the header contents.  Returns true if the
71        // file header could be decoded.
72        bool processFileHeader(size_t* imgDataOffset);
73
74        // An index into |m_data| representing how much we've already decoded.
75        // Note that this only tracks data _this_ class decodes; once the
76        // BMPImageReader takes over this will not be updated further.
77        size_t m_decodedOffset;
78
79        // The reader used to do most of the BMP decoding.
80        OwnPtr<BMPImageReader> m_reader;
81    };
82
83} // namespace WebCore
84
85#endif
86